Back in my childhood I often spent good portions of my summers at my grandparent’s house in East Texas where we got the daily weather forecasts from TV stations in Houston. I vaguely recall that the one my grandparents listened to referred to a “misery index” that, if memory serves me correctly, was calculated by combining the temperature (Fahrenheit) and either the relative humidity or the dew-point to produce a number that, if it exceeded 150, indicated that outdoor conditions were absolutely “miserable”. I tried both these formulai over a period of time myself and found them to be pretty good, but still not always consistent. Through a bit of trial and error over several summers and workouts with a variety of temperatures and humidities, I’ve pretty much settled on the following:

This takes a weighted (2-1) average of the dew-point and relative humidity combined with the temperature and fudges a bit for wind. The optional wind factor includes the fact that the wind’s ability to cool the body is adversely impacted by the relative humidity; and at 100%, has little if any impact. If there is zero humidity, then I estimate that each mile per hour has around a full degree’s worth of cooling impact. I’ve also found it necessary to factor in both the dew-point and the humidity. The 2-1 weighting given to the dew-point was reached via much trial and error.

For example, consider three different Summertime scenarios, all typical around here (Texas): 1) a 90° day with a dew-point of 70°; 2) a 102° degree day with a dew-point of 60°; and 3) a “low for the day” morning 80° temperature with a dew point of 73°. The 90° day thus yields a calculated relative humidity of 52% and the 102° day 25%, and the 80° morning 79%. Using our weighted formula (and assuming no wind for the moment), the 90° day yields a “misery index” of 154, whereas the 102° day yields 148, and in the morning it’s 155! I can assure you that both the 90° day and the 80° morning in our example are indeed noticeably more “miserable” to work out in than the 102° day, but the 102° day is getting pretty close!). It should also be noted that the level of “misery” was nearly just as bad before sunrise as at the mid-day temperature of 90° (so much for better workout conditions in the early morning – I’ve tried early morning workouts and found it to be true that the humidity cancels out the lower temperature)! Now, had we used just the temperature + humidity, these three Summer days would’ve yielded indices of 142, 126, and 159 respectively with neither the two mid-day readings registering as high on the scale as I feel they should and the hotter, dryer day being rated too much less miserable relative to the other than it actually is in experience. The morning value of 159 is way higher than the others (not right). Using just temperature + dew-point would yield 160, 162 and 153 respectively, which also miss the mark with the hotter day being rated slightly more “miserable”. This is the reason for incorporating both values (dew-point and relative humidity) into our formula.

Now, factor in a typical 8 mph breeze to both mid-day readings (we’ll assume no wind for the morning value, which is typical) and you get a four point reduction on the 90° day and a six point reduction on the 102° day as the wind will likely feel about 50% cooler on the dryer day! You can also multiply the final value by 2/3 (0.67) if you wish to have a number that’s closer to a Fahrenheit temperature sale value if you are more comfortable with that. This would produce values of (90° day: 103, 102° day: 99, and the 80° day: 103) respectively.

I’ve been a distance runner and believe that this formula most accurately predicts how “miserable” my workout will be and I usually find it difficult to accomplish much when the index exceeds 150 regardless of the temperature or “heat index”. Generally below 140 and it’s not too bad for a decent workout. I consider 160 and over un-doable due to a high risk of heat-exhaustion! In fact, I’ve written my own “weather app” that runs on my computer that will tell me what the “misery index” is at the moment (along with the temperature and other weather conditions) allowing me to plan outdoor activity accordingly! This, however should not be taken as advise for anyone else in considering their own physical safety when working outdoors and you should know your own body’s limitations and consulting your physician before undertaking physical activity in hot weather!

I heard on WBAP Radio that there’s a new “Aggie Cologne” being marketed now that’s supposed to capture the true Aggie smell! I’m guessing it’s made from a combination of water from the floors of the Corps dorm showers, Johnny Football’s used gym socks, some secret ingredient from the Heldenfeld’s chemistry labs, used grease from Sbisa Dining Hall, and the used hay from Parson’s Mounted Cavalry’s barns!
I also hear it’s expensive, but, after sampling some myself, I figure anyone can get the same “essence” much cheaper by simply not showering or brushing one’s teeth for a couple of weeks. LOL!

Quote of the Day: “The claims that progressives make on the fruits of the labors of others will always be opposed by me because no one has a right to that which belongs to another.” – me